Background: Venous thromboembolism (VTE) is a well-known complication of Achilles tendon rupture (ATR) and carries a high risk of morbidity and mortality. Although routine thromboprophylaxis for patients with ATR is not recommended, sparse knowledge is available regarding risk factors associated with VTE in patients with ATR. Purpose: To use Danish nationwide registers to identify incidence rates for symptomatic VTE and risk factors associated with increased risk of developing VTE in patients with ATR. Study Design: Cohort study; Level of evidence, 3. Methods: By crosslinking nationwide registers, we identified all patients with diagnosed ATR in Denmark from 1997 to 2015. We stratified patients into 4 groups by age and treatment modality (ie, operative vs nonoperative treatment). The main outcome was VTE within 180 days. We calculated crude incidence rates and considered age, sex, year, comorbidities, and medications as risk factors for VTE in Poisson regression models. Results: We identified 28,546 patients with ATR, of whom 389 (1.36%) were hospitalized with VTE during the follow-up period: 278 due to deep vein thromboses and 138 due to pulmonary embolism. Incidence rates were highest during the first month and ranged from 4.6 to 14.6 events per 100 person-years. VTEs were most frequent among nonoperatively treated patients aged ≥50 years. In Poisson regression analyses, having had VTE beforehand was associated with an increased risk of VTE, as was male sex in the nonoperative treatment group aged ≥50 years; among women <50 years of age, hormonal contraceptives led to a 4- to 6-fold higher risk of VTE compared with patients in the same group without the equivalent risk factor. Conclusion: In this nationwide cohort of patients with ATR, 1.36% developed symptomatic VTE during follow-up. Hormonal contraception, previous VTE, older age group, and male sex increased the risk of VTE. Taken together, the results of the present study suggest that focus on risk stratification and initiatives to prevent VTE might be warranted. A randomized controlled trial could answer this question.